The following U.S. Patents and Applications provide background information and are incorporated herein by reference in entirety.
U.S. Pat. No. 6,227,921, which is incorporated herein by reference in its entirety, discloses a marine propulsion device, such as an outboard motor, provided with an oil measuring gage or dipstick which is accessible by the operator of the outboard motor without having to remove the cowl from the device. A first end of the dipstick extends through a dipstick tube into the oil sump of the outboard motor and a second end of the dipstick is connected to a handle that extends through the cowl. The handle is shaped to be retained in a hole formed through the cowl in such a way that the hole is sealed by a portion of the handle to prevent water from passing into the engine compartment through the cowl. A dampening mechanism is provided to dampen vibrations that would otherwise be transmitted between the handle and the dipstick.
U.S. Pat. No. 8,657,638, which is incorporated herein by reference in its entirety, discloses systems for determining oil level in outboard motors comprise an internal combustion engine, a control circuit that determines whether oil has drained into a sump from the internal combustion engine, and an oil sensor sensing the oil level in the sump. The control circuit can calculate a characteristic of the oil level based upon the sensed oil level after the oil has drained back into the sump and based upon a trim position of the outboard motor. In other examples, methods of determining oil level in a marine outboard motor include determining, with a control circuit, that oil has drained into a sump from an internal combustion engine in the outboard motor; sensing an oil level in the sump once the oil has drained back into the sump; and calculating, with the control circuit, a characteristic of the oil level of the outboard motor based upon the sensed oil level and a trim position of the outboard motor.